Schematic representation of the variation in the angular momentum for different injection scenarii. The distance to the centre in this diagram represents the angular momentum of the comets, i.e., the perihelion distance in the present case of quasi-parabolic orbits. The full black circle corresponds to a perihelion distance of 15 AU, and the yellow disk corresponds to perihelion distances smaller than 5 AU. The meaning of the arrows is explained in the text. For each trajectory, the comet starts at perihelion before its last revolution.